Oil leak from top of cam cover?

[Trish&Brian]

I have an unsightly oil leak and it seems to be coming from a fixing on the top of the cam cover. This seems unlikely I know but the oil stains seem to indicate that. See pics below. My question is whether I am on the right track and, if so, what sort of fixing is involved?

I tried a 4mm Allen key which was too small and a 5mm was too big. Could it be a 4.5mm? Or does it use some other sort of key? Also, does it have some sort of rubber or copper sealing washer that might need replacing?

Sorry for all the questions. Just wish I had smaller hands to make access a bit easier!

Brian

[mikeonb4c]

If you don't mind doing a little extra work, access would become a cinch if you unbolted and removed the centre section of the cover (I seem to remember being a bit baffled as to how to remove the gear selector knob but worked it out in the end).

But maybe that is a sledge hammer to crack a nut. It doesn't look like much oil, suggesting its a v slow seepage (Bongo engines can be a bit oily anyway - at least the 2.5TD can be, from personal experience). It might be worth gunking it off to thoroughly degrease it and then trying to find a suitable material to make a circle shaped repair patch from. Just possible it might hold, and stop the slow seepage. Not sure what would work best but obviously something OK with engine rocker cover temps (maybe that tape used for taping up leaking radiator hoses might do, or search ebay / web for high temperature tape). Bit of a cheat I know but simple and might save hassle so worth a try.

[helen&tony]

Hi
Just had the rocker cover off, and don't remember a fixing there, but if there is, drill it, tap it, and fit a sawn-off bolt in with Hylomar whilst the cover's off, and fit a new gasket at the same time...The whole issue is an easy job.
Cheers
Helen

[Simon Jones]

If I recall correctly, inside the top of the rocker cover is a flat metal baffle, so there should be no way that oil can splash out the top. I dont believe there is a hole in that part of the casting, but it is possible that it can crack very easily as the metal is very fragile. I've got a spare rocker cover in the garage & managed to snap a whole chunk off just by moving from place to place.

Looking at the oil pattern towards the rear of the rocker cover I would say it is actually moving up the casting rather than dripping down. This could be due to a leak on the seals round the mounting bolt, or even just the movement of air while travelling & from the scavenger fan. The first two bolts in the photo are particularly oily so it could be leaking from the bolts or the gasket. You can get a new gasket & set of 12 (?) seals for the bolts from about £15 on ebay so I personally would change the lot for piece of mind.

[Trish&Brian]

Thanks for the prompt and helpful replies!

I have had another look and most of the "wet" or fresh oil seems to be at the front of the cam cover so am leaning towards the suggestion that it is the cam cover gasket leaking and the oil being blown up over the cam cover rather than the oil seeping from the fixing on the top as I first thought.

I think a good degrease and a watch where the fresh oil appears is on the cards

Thanks again!

Brian

[mikeonb4c]

I think a good degrease and a watch where the fresh oil appears is on the cards

I agree completely - that's the first thing to do, and it should reveal (1) where the source is and (2) whether it is happening at a rate worth fussing over. To repeat, diesel Bongo engines are not noted for their pristine look so why worry - just shut up and drive, as the song goes